Polyphenol profile and antioxidant capacity of a traditional Sicilian landrace of the Egyptian Walking Onion (Allium cepa L. var. viviparum)

Nowadays, consumers pay increasingly more attention to the health-promoting aspect of meals. Among them, vegetables show high richness in valuable antioxidant compounds in their products. One example is onion (Allium cepa L.), which has been known and used worldwide for centuries. Onion is a valuable raw material largely used in food industry. Low production cost makes it an important crop in developing countries providing opportunities to meet with food demand and supply chain. A number of authors have shown that onions possess many biological activities including antibacterial, anticancer, hypoglycemic, hypolipidemic, antiplatelet aggregation and antioxidant. Among onions, the Egyptian Walking Onion (Allium cepa L. var. viviparum), a traditional neglected crop grown in Sicily, could be exploited for diversification of ready-to-eat products. The goal of our work was to compare the total polyphenol content of the Egyptian Walking Onion with five landraces of onion (Allium cepa var. cepa) of different bulb color. Additionally, the analyses of ascorbic acid and carotenoids content were performed. The quantitative and qualitative polyphenol contents were detected by HPLC and the antioxidant capacity analysis was ascertained by DPPH and ROO. Our results showed different qualitative and quantitative traits between the var. cepa and var. viviparum of A. cepa and they have been discussed.